1. Field of Invention
The invention relates to an extractor for injection-molding machine for processing plastifiable compounds.
2. Prior Art
An injection molding machine of the aforementioned type is described in European Patent 0 624 448 A1, wherein the extractor therein is guided inside a crank member with an involved, three-dimensional, curved cylinder surface. The extraction means for the above extractor is arranged crosswise to the clamping axis. As a result, further space is needed in addition to the mold-clamping chamber, which space also necessitates an additional protective device. Thus, in the exemplary embodiment shown in FIGS. 11-14, a considerable expenditure is required to arrange the extractor underneath a corresponding protective device that is required in most industrial countries. The extractor itself is guided with a guide pin inside a crank guide. However, the actuation element in connection with the two drive motors requires additional space, since the two drive motors are not designed to be pivotable, nor is the actuation element itself guided inside the crank guides.
An extractor is known from U.S. Pat. No. 3,773,457, which is guided by a crank that extends essentially crosswise to the clamping axis. In this case, additional space is also required in the plane perpendicular to the clamping axis, which space would have to be covered by a protective device if this principle were to be transferred to an injection-molding machine. The additional space is furthermore required because the crank guide and the point of contact for the drive unit are separate, which is made clear by a comparison of FIGS. 3 and 4.
An injection-molding machine with an extractor is furthermore disclosed in the European Patent A 359 013. The extractor therein is a handling device, which is designed to remove molded articles from the mold-clamping chamber. For that purpose, a multi-axis system is provided, which permits an accurate removal of the molded articles as well as an exact depositing of the molded articles in receiving openings. Apart from the coordination of the three axes, an amount of space is required above the injection-molding machine, which should not be underestimated and, for the most part, requires a customized production of the protective device.
An extractor with two axes is known from European Patent A 218 101, wherein the second axis in the symmetry plane for the injection-molding unit is submerged perpendicular to the dividing plane. The perpendicular axis in this case also requires a considerable amount of space.
Starting with this prior art, it is the object of the present invention to create an extractor for an injection-molding machine of the aforementioned generic type, which requires less space.
This object is solved with an injection-molding machine for processing plastifiable compounds, comprising: a mold-clamping unit for accommodating an injection mold, the mold clamping unit including a mold clamping chamber and a clamping mechanism for opening and closing the injection mold in the mold clamping chamber in a direction of a clamping axis; an extractor comprising an extraction means for removing articles produced during an injection molding process from an opened injection mold; a crank element with a crank guide defining a guide path curved away from the clamping axis and having a longitudinal extension substantially parallel to the clamping axis; a drive unit for moving the extractor along the crank guide, said drive unit having a driving movement and including a first end and a second end, said driving movement being substantially parallel to the clamping axis and the longitudinal extension of the crank guide; and a guide unit connected to the drive unit and the extractor, said guide unit being guided at least at two locations on the crank guide, wherein the first end of the drive unit is pivotably attached to the crank element and the second end of the drive unit is attached with hinges to the guide unit, and wherein the driving movement of the drive unit moves the guide unit along the guide path, for moving the extraction means in and out of the injection mold.
The extractor is essentially activated by means of a drive unit and is positioned in the mold-clamping chamber with the aid of a crank guide, which essentially extends parallel to the clamping axis. The crank guide operates jointly with the drive unit, so that no additional space or very little additional space is required. The basic structural requirements for installing the extractor are therefore already provided by the areas claimed for the injection-molding machine. As a result, the extractor can be arranged underneath existing protective devices, so that existing machines can be retrofitted at any time without problems.
According to the cited references, not only was additional space required for the extractor, which had to be covered with a separate protective device, but involved deflection means were also provided to achieve a static determination of the drive unit. Above all, the drive unit according to our application is positioned such that it is articulated at both ends. For a static determination and to be able to guide the extractor with precision to the extraction point, the guide unit itself nonetheless must be positioned in at least two locations inside the crank guide in such a way that an unambiguous position is ensured for any operational state. At the same time, the crank guide and the drive unit are arranged such that the main movement direction and the longitudinal extension are in the direction of the clamping axis, so that the extractor does not require additional space when it is pivoted out. Despite this, the extractor can be assembled easily from a few structural elements.